A wide variety of soil release agents for use in domestic and industrial fabric treatment processes such as laundering, fabric drying in hot air clothes dryers, and the like are known in the art. Various soil release agents have been commercialized and are currently used in detergent compositions and fabric softener/antistatic articles and compositions. Such soil release polymers typically comprise an oligomeric or polymeric ester “backbone”.
Until now the development of an effective cotton soil release agent for use in a laundry detergent has been elusive. Attempts by others to apply the paradigm of matching the structure of a soil release polymer with the structure of the fabric, a method successful in the polyester soil release polymer field, has nevertheless yielded marginal results when applied to cotton fabric soil release agents. The use of methylcellulose, a cotton polysaccharide with modified oligomeric units, proved to be more effective on polyesters than on cotton. For example, U.K. 1,314,897, published Apr. 26, 1973 teaches a hydroxypropyl methyl cellulose material for the prevention of wet-soil redeposition and improving stain release on laundered fabric. U.S. Pat. No.3,897,026 issued to Kearney, discloses cellulosic textile materials having improved soil release and stain resistance properties obtained by reaction of an ethylene-maleic anhydride co-polymer with the hydroxyl moieties of the cotton polymers. U.S. Pat. No. 3,912,681 issued to Dickson teaches a composition for applying a non-permanent soil release finish comprising a polycarboxylate polymer to a cotton fabric, at a pH less than 3. U.S. Pat. No. 3,948,838 issued to Hinton, et alia describes high molecular weight (500,000 to 1,500,000) polyacrylic polymers for soil release, used preferably with other fabric treatments. U.S. Pat. No. 4,559,056 issued to Leigh, et alia discloses a process for treating cotton or synthetic fabrics with a composition comprising an organopolysiloxane elastomer, an organosiloxaneoxyalkylene copolymer crosslinking agent and a siloxane curing catalyst. Other soil release agents not comprising terephthalate and mixtures of polyoxy ethylene/propylene are vinyl caprolactam resins as disclosed by Rupert, et alia in U.S. Pat. Nos. 4,579,681 and 4,614,519. Examples of alkoxylated polyamines and quaternized alkoxylated polyamines are disclosed in European Patent Application 206,513 as being suitable for use as soil dispersents. WO97/42288 describes effective soil release agents for cotton articles that can be prepared from certain modified polyamines available to all cotton articles whether laundered in the presence of a bleaching agent or not. In addition to the above cited art, the following disclose various soil release polymers or modified polyamines; U.S. Pat. No. 5,565,145, Watson et al., issued Oct. 15, 1996; U.S. Pat. No. 4,548,744, Connor, issued Oct. 22, 1985; U.S. Pat. No. 4,597,898, Vander Meer, issued Jul. 1, 1986; U.S. Pat. No. 4,877,896, Maldonado, et al., issued Oct. 31, 1989; U.S. Pat. No. 4,891,160, Vander Meer, issued Jan. 2, 1990; U.S. Pat. No. 4,976,879, Maldonado, et al., issued Dec. 11, 1990; U.S. Pat. No. 5,415,807, Gosselink, issued May 16,1995; U.S. Pat. No. 4,235,735, Marco, et al., issued Nov. 25, 1980; WO 95/32272, published Nov. 30, 1995; U.K. Patent No. 1,537,288, published Dec. 29, 1978; U.K. Patent No. 1,498,520, published Jan. 18, 1978; German Patent DE 28 29 022, issued Jan. 10, 1980; Japanese Kokai JP 06313271, published Apr. 27, 1994.
However the use of such cotton soil release polymers is not effective enough to protect the garments from stain encrustation, in particular from cosmetic and food stains. Indeed modern cosmetic and food compositions contain more and more additives such as hydrocolloid gums used as thickeners. Mannans, Guar gum and Locus Bean are used in several cosmetic and food composition (see Industrial Gum, second editions, R. L. Whistler pp 308, Academic Press, 1973, ISBN, 0-12-74-6252-x). It is known that these hydrocolloid gums have a very high affinity for cellulose materials and are hard to remove. At present, the use of cotton soil release polymer is not sufficient to tackle this cosmetic/food stains encrustation.
Food and cosmetic stains/soils represent the majority of consumer relevant stains/soils and often comprise food additives such as thickener/stabiliser agents. Indeed, hydrocolloids gums and emulsifiers are commonly used food additives. The term “gum” denotes a group of industrially useful polysaccharides (long chain polymer) or their derivatives that hydrate in hot or cold water to from viscous solutions, dispersions or gels. Gums are classified as natural and modified. Natural gums include seaweed extracts, plant extrudates, gums from seed or root, and gums obtained by microbial fermentation. Modified (semisynthetic) gums include cellulose and starch derivatives and certain synthetic gums such as low methoxyl pectin, propylene glycol alginate, and carboxymethyl and hydropropyl guar gum (Gums in Encyclopedia Chemical Technology 4th Ed. Vol. 12, pp842-862, J. Baird, Kelco division of Merck). See also Carbohydrate Chemistry for Food Scientists (Eagan Press—1997) by R. L. Whistler and J. N. BeMiller, Chap 4, pp63-89 and Direct Food Additives in Fruit Processing by P. Laslo, Bioprinciples and Applications, Vol1, Chapter II, pp313-325 (1996) Technomie publishing. Some of these gums such as guar gum (E412), locust bean (E410) are widely used alone or in combinations in many food applications (Gums in ECT 4th Ed., Vol. 12 pp842-862, J. Baird, Kelco division of Merck).
The guar gum used in these food and cosmetic stains is obtained from the seed endosperm of the leguminous plant Cyamopsis tetragonoloba. The guar gum (also called guaran) extracted from the dicotyledonous seed is composed of a 1-4, b-D-mannopyranosyl unit backbone and is used as a thickening agent in dressing and frozen products and cosmetics (H.-D. Belitz, Food Chemistry pp 243, English version of the second edition, Springer-veriag, 1987, ISBN 0-387-15043-9 (US)) & (Carbohydrate Chemistry for Food Scientists, R. L. Wilstler, eagan press, 1997, ISBN 0-913250-92-9) & (industrial Gum, second editions, R. L. Whistler pp 308, Academic Press, 1973, ISBN, 0-12-74-6252-x). The locus bean gum (also called carob bean gum or St Jon's bread) is also used in the food industry and is extracted from the seed of an evergreen cultivated in the Mediterranean area. The locus bean gum probably differs from the structure of guar gum only in smaller number of D-galactosyl side chains and have the same 1-4, b-D-mannopyranosyl backbone. In leguminous seeds, water-soluble galactomanann is the main storage carbohydrate, comprising up to 20% of the total dry weight in some cases. Galactomannan has a α-alactose linked to O-6 of mannose residues and it can also be acetylated to various degree on O-2 and O-3 of the mannose residues.
As described above, there is a continuous need to formulate laundry detergent compositions which provide superior cleaning performance, especially on cosmetic and food stains and soil release benefits. This objective has been met by formulating laundry detergent compositions comprising a mannanase and a cotton soil release polymer.
It has been further found that the performance of the laundry detergent compositions of the present invention is enhanced by the addition of another detergent ingredient selected from a builder, especially a zeolite, a sodium tripolyphosphate and/or layered silicate, a surfactant, preferably a nonionic surfactant such alkyl ethoxylate or alkyl methyl glucamide, a conventional soil release polymer and/or mixtures thereof.
Mannanases have been identified in several Bacillus organisms. For example, Talbot et al., Appl. Environ. Microbiol., vol. 56, No. 11, pp. 3505-3510 (1990) describes a β-mannanase derived from Bacillus stearothermophilus in dimer form having a MW of 162 kDa and an optimum pH of 5.5-7.5. Mendoza et al., World J. Micobio. Boitech., vol. 10, no. 5, pp. 551-555 (1994) describes a β-mannanase derived from Bacillus subtilisis having a MW of 38 kDa, an optimum activity at pH 5.0/55° C. and a pI of 4.8. J0304706 discloses a β-mannanase derived from Bacillus sp. having a MW of 37+/−3 kDa measured by gel filtration, an optimum pH of 8-10 and a pI of 5.3-5.4. J63056289 describes the production of an alkaline, thermostable β-mannase, which hydrolyses β-1,4-D-mannopyranoside bonds of e.g. mannans and produces manno:oligo:saccharides. J63036774 relates to a Bacillus microorganism FERM P-8856 which produces β-mannanase and β-mannosidase, at an alkaline pH. A purified mannanase from Bacillus amyloliquefaciens and its method of preparation useful in the bleaching of pulp and paper, is disclosed in WO97/11164. WO91/18974 describes an hemicellulase such as a glucanase, xylanase or mannanase, active at extreme pH and temperature and the production thereof. WO94/25576 describes an enzyme exhibiting a mannanase activity derived from Aspergillus aculeatus CBS 101.43, that might be used for various purposes for which degradation or modification of plant or algae cell wall material is desired. WO93/24622 discloses a mannanase isolated from Trichoderrna reesie for bleaching lignocellulosic pulps.
However, the synergistic combination of a mannanase and cotton soil release polymer, for superior cleaning and soil release performance in a laundry detergent composition, has never been previously recognised.